We are Living in an Ancestor Simulation

Now we get to the core of the simulation argument. This does not purport to demonstrate that you are in a simulation. Instead, it shows that we should accept as true at least one of the following three propositions:

(1) The chances that a species at our current level of development can avoid going extinct before becoming technologically mature is negligibly small

(2) Almost no technologically mature civilisations are interested in running computer simulations of minds like ours

(3) You are almost certainly in a simulation.

Each of these three propositions may be prima facie implausible; yet, if the simulation argument is correct, at least one is true (it does not tell us which).

While the full simulation argument employs some probability theory and formalism, the gist of it can be understood in intuitive terms. Suppose that proposition (1) is false. Then a significant fraction of all species at our level of development eventually becomes technologically mature. Suppose, further, that (2) is false, too. Then some significant fraction of these species that have become technologically mature will use some portion of their computational resources to run computer simulations of minds like ours. But, as we saw earlier, the number of simulated minds that any such technologically mature civilisation could run is astronomically huge.

Therefore, if both (1) and (2) are false, there will be an astronomically huge number of simulated minds like ours. If we work out the numbers, we find that there would be vastly many more such simulated minds than there would be non-simulated minds running on organic brains. In other words, almost all minds like yours, having the kinds of experiences that you have, would be simulated rather than biological. Therefore, by a very weak principle of indifference, you would have to think that you are probably one of these simulated minds rather than one of the exceptional ones that are running on biological neurons.

So if you think that (1) and (2) are both false, you should accept (3). It is not coherent to reject all three propositions. In reality, we do not have much specific information to tell us which of the three propositions might be true. In this situation, it might be reasonable to distribute our credence roughly evenly between the three possibilities, giving each of them a substantial probability.

Periodicals>Journal Article:Bostrom, Nick (May 16, 2003), The Simulation Argument: Why the Probability that You Are Living in a Matrix is Quite High, Times Higher Education Supplement, Retrieved on 2015-04-01